Bituminous roofing products and process

ABSTRACT

A NON-WOVEN FIBROUS WEB IS AFFIXED TO THE COATING LAYER OF HOT BITUMEN COMMONLY APPLIED TO ROLL OR SHINGLE FORM ROOFING PRODUCTS. THE FIRBOUS WEB PREVENTS THE PRODUCTS FROM STICKING TOGETHER WHEN ROLLED OR STACKED.

United States Patent Oflice 3,813,280 BITUMINOUS ROOFING PRODUCTS AND PROCESS Bernard John Olszyk, Somerville, and Richard Leon Fricklas, Bound Brook, N.J., assignors to Johns-Manville Corporation, New York, N.Y.

Filed Sept. 9, 1971, Ser. No. 178,870 Int. Cl. E04d 5/10 US. Cl. 161-151 13 Claims ABSTRACT OF THE DISCLOSURE A non-woven fibrous web is afiixed to the coating layer of hot bitumen commonly applied to roll or shingle form roofing products. The fibrous web prevents the products from sticking together when rolled or stacked.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to hot bitumen-coated products and their production, and more particularly to an improved process for imparting non-stick properties to hotcoated roofing materials, and to the non-stick products produced by the process.

Discussion of the prior art In the production of bituminous roofing, whether in roll form or as shingles, it is usually necessary to apply an anti-stick agent to the coating asphalt to prevent blocking or sticking together of the roofing when it is rolled or stacked for shipping and handling. The anti-stick agent normally takes the form of a finely divided mineral product, such as talc, mica or sand. Other methods of preventing sticking include the application of a soap solution to the asphalt coating.

Although anti-stick agents heretofore used with bituminous roofing have usually provided satisfactory antistick properties, they exhibit undesirable properties under some manufacturing and service conditions. For example, if a finely divided anti-stick material, such as sand, talc or mica is used, a serious dust problem exists during production of the roofing. It is also difiicult to apply a uniform quantity of powdered anti-stick material to the roofing product. Uniformity of application of the powdered antistick material is important because too little of the antistick material will not function to prevent sticking together of the roofing when rolled or stacked, and too much of the anti-stick material results in non-adhesion during construction of built-up roofing.

Dusty or powdered anti-stick materials can also create additional problems on the job. For example, if sand is used, excess sand frequently deposits on the roofing surface during installation to create a stability hazard for workmen moving about on the roofing surface.

The use of soap solutions as anti-stick agents is also troublesome. They are ditficult to control, and the degree of anti-stick properties achieved cannot be readily determined. In addition, soap solutions must be applied in an aqueous system and the water must be removed after application. This, of course, adds another step to the production process.

SUMMARY OF THE INVENTION The invention provides superior anti-stick properties for a bituminous roofing product and comprises a bitumensaturated fibrous felt having first and second bituminous coating layers applied to opposite sides of the felt, and a non-stick material applied to at least the first coating layer. Specifically, a non-woven, non-hygroscopic fibrous web is adhered to the first coating layer to prevent the first layer from sticking to surfaces contacted thereby during shipping and handling. Non-woven webs can be provided on either one or both of the bituminous coating layers. For example, shingles having mineral granules adhered to one coating layer require only one web due to the presence of only one sticky exposed layer. Preferably, for products which do not include a mineral granule coating, such as smooth roll roofing, both bitumen coating layers will have non-woven webs laminated thereto to provide antistick properties.

The invention also provides an improvement in a selfsealing shingle of the type including a butumen-saturated felt, first and second bitumen coating layers on opposite sides of the melt, a layer of mineral granules bonded on the first coating layer, and areas of a resinous adhesive adhered on the outer surface of the mineral granule layer to provide the shingle with self-sealing properties. The improvement comprises a non-woven web of non-hygroscopic fibers aflixed to the second coating layer in laminar contact therewith; and a coating of a release agent on selected areas of the outer surface of the fibrous web. The release agent is present at areas that are positioned in abutting contact with areas of the resinous adhesive of an adjacent shingle when a plurality of shingles are stacked for handling or storage.

The invention further encompasses an improved method of providing non-blocking properties to one side of a bitumen-saturated fibrous felt that has been coated with hot bitumen. A non-woven web of non-hygroscopic fibers is forced into contact with the hot bitumen coating, and subsequently the bituminous coating is cooled, with the bitumen adhering to the web.

The use of a web of non-woven fibers as a substitute for prior art anti-stick agents such as talc, mica, or sand, or soap solutions, makes an asphalt roofing products manufacting operation relatively dust free and eliminates any drying operation needed to remove water. The laminated roofing product including at least one non-woven web has a desirably uniform thickness and better strength properties when compared to comparable asbestos felt products coated with an anti-stick agent. A roofing product which has a non-uniform thickness may provide thin spots where base to which bitumen can bond. This latter property is important in built-up roof applications where a layer of hot liquid asphalt is applied to the asphalt roofing paper.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate examples of preferred embodiments of the invention, and together with the description, serve to explain the principles of the invention.

In the drawings:

FIG. 1 is a fragmentary vertical cross-section of one embodiment of the invention;

FIG. 2 is a fragmentary vertical cross-section of another embodiment of the invention;

FIG. 3 is a plan view of an embodiment of a self-bonding roofing shingle constructed in accordance with the invention;

FIG. 4 is a vertical cross-sectional view of the shingle illustrated in FIG. 3 taken along the line 4-4; and

FIG. 5 is a plan view of a pair of the shingles illustrated in FIG. 3 showing the relative positioning of adjacent shingles when installed.

With reference now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIG. 1 a cross-section of a smooth roll roofing product including a felt layer 10. The felt is preferably a dry felt formed of rag, paper, or wood fibers according to conventional paper making techniques. The felt is then saturated and impregnated with a saturant material, such as asphalt, in a conventional manner. A first coating layer 12 is applied to one side of felt layer 10, and a second coating layer 14 is applied to the other side of the felt layer. Each of the coatings 12 and 14 is preferably asphalt and is hot when applied to felt layer 10. These coatings are aiso applied by conventional procedures.

The preservative and waterproofing characteristics of asphalt reside very largely in certain oily constituents. Therefore, in the manufacture of roofing it is desirable to impregnate or saturate the body of the sheet of highly absorbent felt to the greatest possible extent with a type of oil-rich asphalt known as saturaut, and then to seal the saturant in with an application of a harder, more viscous coating asphalt which itself can be protected, if desired, by a covering of opaque mineral granules.

It is the presence of the coating layers of asphalt which creates the sticking problems that are experienced unless some preventive action is taken. In the past, fine mineral particles have been dusted on the surfaces of smooth roll roofings, the back of mineral surfaced roll roofings and the backs of shingles for the primary purpose of preventing the convolutions of the roll from sticking together after it is wound, and of preventing shingles from sticking together in the package. The particles are not intended to be a permanent part of the finished product and will gradually disappear from exposed surfaces after the roofing is applied. Problems stemming from these prior art techniques have already been discussed.

In accordance with this invention, a non-woven fibrous Web 16 of substantially uniform thickness is applied to first coating 12 after application of coating 12 to felt layer 10. Web 16 can be forced into heated coating 12 by roll pressure or the like. The web and coating 12 are then cooled with a water spray or by forced air circulation or by other means so that the web becomes affixed to the cooled coating 12.

If desired, a second non-woven fibrous web 18, similar to web 16, may be applied to second asphalt coating 14 in a manner similar to that described for the application of web 16.

An alternative embodiment of the invention is illustrated in FIG. 2. In this arrangement non-woven web 16 is applied to first asphalt coating 12 in the manner previously described. However, instead of applying a nonwoven web on the second coating 14, coarse mineral aggregates or granules 20 are applied to second asphalt coating layer 14 to provide a mineral-surfaced product.

Non-woven webs 16 and 18 of this invention are dustfree and are preferably of uniform thickness. The webs are prepared by arranging the fibers using either conventional dry or wet forming techniques. The arranged fibers are then adhesively, thermally, or solvent bonded together to form an integral web. If desired, the fibers may be mechanically interlocked without any inter-fiber chemical bond. The webs preferably weigh between about 1 oz. per square yard or less to about 6 oz. per square yard, more preferably not more than about 1 oz. per square yard, and preferably have a thickness of between about mils or less to about 30 mils. The fibers in the web may be continuous or staple length and include polyester, polyethylene or other polyolefins, nylon, glass or other synthetic, non-hygroscopic fibers.

With reference now to FIGS. 3-5, there is shown an embodiment of the present invention in the form of a selfbonding shingle. As shown in FIG. 4, the shingle generally 23 has the general laminar structure of the embodiment of FIG. 2. Areas 22 of conventional. roofing adhesive material are positioned in selected locations on granules at the surface of the shingle to provide a selfsealing laminate or roofing shingle. A non-adhesive release agent 24, such as a petroleum wax or a silicone polymer is adhered to selected locations on non-woven fibrous web 16 to prevent the shingles from sticking together when stacked in a package due to the presence of areas 22 of adhesive material. The area covered by release agent 24 will usually be a strip that is wider than the width of the areas of adhesive material.

The release agent 24 preferably extends in a strip along the entire length of the laminate or shingle (FIG. 3) and is positioned in alignment with the areas of adhesive and on the opposite side of the web as the adhesive. Thus, when the shingles are rolled or stacked the release agent 24 will contact adhesive 22. However, as shown in FIG. 5, when the shingles are installed in the normal off-set position, adhesive areas 22 contact non-woven web 16 along edge 28 of the shingle. As a result, a good bond is created between adhesive material 22 and non-woven web 16, and edge 28 of the shingle is sealed down in the desired manner.

The present invention, thus, provides a roofing laminate structure that prevents the laminate from sticking to similar laminates during shipping and handling. A light weight non-woven fibrous web prevents sticking of the laminate when rolled or stacked and provides the additional advantages of being dust free, protecting the asphalt coating from developing perforated or void areas, adding reinforcement to the felt layer of the laminate, providing a good base to which the asphalt can bond when the laminate is designed to be scaled down, and providing additional tear strength to the laminate.

The invention in its broader aspects is not limited to the specific details shown and described and departures may be made from such details without departing from the principles of the invention and without sacrificing its chief advantages.

What is claimed is:

1. In a bituminous roofing product comprising a bitumen-saturated fibrous felt having first and second bituminous coating layers applied to opposite sides of the felt, the improvement comprising: a non-woven, nonhygroscopic fibrous web adhered in laminar relationship with said first coating layer to prevent said first layer from sticking to surfaces contacted thereby during shipping and handling.

2. A roofing product as in claim 1 wherein the first and second bituminous coating layers are comprised of asphalt.

3. A roofing product laminate as in claim 1 in which a non-woven fibrous web is afiixed in laminar relationship to said second coating layer to prevent said second coating layer from sticking to other surfaces during shipping and handling.

4. A roofing product as in claim 1 in which coarse mineral granules are affixed to said second coating layer.

5. A roofing product as in claim 1 wherein said nonwoven fibrous web weighs up to about 6 oz. per square yard, and is of substantially uniform thickness.

6. A roofing product as in claim 5 wherein said nonwoven fibrous web weighs less than about 1 oz. per square yard.

7. A roofing product as in claim 1 wherein the nonwoven fibrous web is comprised of non-hygroscopic fibers selected from the group consisting of polyolefin, nylon, glass, and polyester fibers.

8. In a self-bonding roofing shingle comprising a bitumen-saturated, felt, first and second bitumen coating layers on opposite sides of said felt, layer of mineral granules adherently bonded on said first coating layer, and areas of a resinous adhesive adhered on the outer surface of the mineral granule layer to provide the roofing shingle with self-bonding properties, the improvement comprising: a non-woven web of non-hygroscopic fibers afiixed to the second coating layer in laminar contact therewith; and a coating of a release agent on selected areas of the outer surface of said fibrous web, said release agent being present at areas that are positioned in abutting contact with areas of resinous adhesive when a plurality of shingles are stacked for handling or storage.

9. The shingle of claim 8 wherein said release agent extends in a strip across the length of the laminate.

10. The shingle of claim 7 wherein said release agent is a petroleum wax.

11. The shingle of claim 8 wherein said release agent is a silicone-containing polymer.

12. In the manufacture of bituminous roofing products in web form, an improved method of providing non-blocking properties to one side of a bitumen-saturated fibrous felt that has been coated with hot bitumen, comprising: bringing a non-woven web of non-hygroscopic fibers into laminar contact with the hot bitumen coating on said one side and subsequently cooling said bituminous coating.

13. The method of claim 12 including the step of bringing a second non-woven web of non-hygroscopic fibers into laminar contact with a hot bitumen coating on the other side of said bitumen-saturated felt.

References Cited UNITED STATES PATENTS 820,470 5/1906 Bird 161-167 3,111,787 11/1963 Chamberlain 156-337 3,402,095 9/1968 Varfeldt 161-236 10 GEORGE F. LESMES, Primary Examiner S. S. SILVERMAN, Assistant Examiner US. Cl. X.R. 

